Johnson 6 hp, idling rpm when throttle over 3/4

[charles.wahlin]

I have a problem with idling rpm when throttle is over 3/4. There is no other problem with the engine. Everything else is working fine. Does anyone know what the problem might be?<br /><br />/ Charles

 

[12Footer]

Re: Johnson 6 hp, idling rpm when throttle over 3/4

If the engine isn't missfiring, and it is just low RPM, it has to be linkage related.<br />If you meant to say it has normal RPM but boat just idles, it's the hub in the prop.<br />Anything alse,and the engine would stumble,not run at an even speed,or missfire.

 

[charles.wahlin]

Re: Johnson 6 hp, idling rpm when throttle over 3/4

Sorry for my bad english.<br />What I mean is that the rpm goes up and down when I throttle over 3/4. A small variation in speed. It makes me wonder if the engine will stop working, but I know it will not.<br />It's rather my wifes father that is a little bit suspicious. I suspect it might be some problem with the carburator, but I really don't know. There is no misfire and nothiong wrong with the transmission. It must be something with the fuel system.<br />/ Charles

 

[JB]

Re: Johnson 6 hp, idling rpm when throttle over 3/4

Howdy, Charles. I think 12Footer identified the problem: the hub {or shear pin) on your prop needs replacement. At least I think so based on my understanding of your description.<br /><br />Good luck.<br />JB

 

[Dunk]

Re: Johnson 6 hp, idling rpm when throttle over 3/4

If the engine is surging at 3/4 throttle I'd be checking the fuel line for air leaks first. Make sure the plug connectors have the orings in place and snap on the tank and engine tight. Along with the rubber fuel lines on the engine to the fuel pump and from the pump to the carb. Make sure the screw on fliter(knurled knob) on the fuel pump is tight. If she's pulling air at any of there fittings the pump will be pushing air to the carb and not keeping it full. If all is well above then rebuild the fuel pump.

 

[charles.wahlin]

Re: Johnson 6 hp, idling rpm when throttle over 3/4

Hi!<br />I've read your solutions. I sure will try them. Ithink I will start with the idea from Dunk.<br />I've recently put my boua into the sea, so I can test it.<br />Thanks a lot for your interest.<br /><br />/Charles